The Omagh bomb families have used the 18th anniversary of the atrocity to pray for victims of terrorism around the world.
Several hundred people attended a service in the town yesterday to remember those who died in the 1998 attack.
Yesterday's event took place close to the scene of the blast, which claimed the lives of 29 people, including a woman pregnant with twins.
Michael Gallagher, who lost his son Aidan in the atrocity, said: "It was a very moving service.
"We prayed for all of the victims of terrorism at home and around the world."
In the 12 months since the previous service there has been a series of atrocities in Germany, France and Belgium.
Prayers were also said for Adrian Ismay, the prison officer murdered by an under-car bomb earlier this year, and Michael McGibbon, who was shot dead in a punishment-style attack in April.
The Omagh bombing was the biggest single atrocity in the history of the Troubles in Northern Ireland.
The 500lb device exploded in Market Street on August 15, 1998 - just four months after the Good Friday Agreement was signed.
The death toll included nine children and three generations of one family, but no one has been convicted in a criminal court of carrying out the attack.
Yesterday's memorial was an inter-denominational service.
Among those present was Rabbi David Singer from the Jewish community, and senior members of the Islamic Centre in Belfast.
Mr Gallagher added: "As always there were three elements to our service - a Spanish element, an Irish element and an English element, representing the three nations affected by Omagh."
St Eugene's brass band as well as the Omagh Community Choir performed music at the service.
Mr Gallagher added: "We had several hundred people present, many of whom had travelled great distances to be with us.
"We actually had one visitor from Cork, who attends every year."